Not steam mostly but check out Eifelquerbahn in the Koblenz area. And Rhein in Flammen fireworks.
Unfortunately the Eifelquerbahn is no more :cry:
"The volcano Eifel-Bahn Betriebsgesellschaft mbH (VEB) regrets communicated to, that more will be 2013 no leisure traffic season of the Eifel railway. For 12 years, rattled the historic Railbuses until October in the 2-hourly between Daun, Gerolstein and Kaisersesch, ELMS now from may, in the summer, complemented by the very popular steam trains and transported several hundred thousand passengers. We would like to further offered the rides, however, it lacks funds for much-needed investment to the maintenance of the rail infrastructure. Unfortunately they could not provided on the part of the State of Rhineland-Palatinate also, as the Vulkaneifel district day with a majority of CDU and citizens Union Vulkaneifel (BUV) has spoken out against the Eifel railway. Rien ne va plus!
The VEB thanked for the support over the years and hopes that the Eifel railway remains all passengers in good memories with your Railbuses and the always friendly service on the trains!" - translated by Google
It is not local (about an hour away) and not steam either, but I have done the Drachenfels railway at Königswinter and would recommend it